The purpose of this study is to examine the disposition of 3 nonsteroidal anti-inflammatory drugs which are metabolized to acyl glucuronides and to examine the characteristics of protein glycation by acyl glucuronides in elderly (>55 years) patients with varying renal function but not receiving chronic NSAID therapy. Since the primary route of elimination of glucuronides from the body is through renal or biliary excretion, accumulation of glucuronides in plasma can be exaggerated by renal impairment.